Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX
To investigate a patient presenting with syncope where Long QT Syndrome (an inherited cardiac condition) is suspected, the following investigations are recommended:
- Initial Assessment and Referral: A patient with syncope and a family history of sudden cardiac death in people aged younger than 40 years and/or an inherited cardiac condition should be referred for an urgent specialist cardiovascular assessment within 7 days NICE CG109.
- Specialist Cardiovascular Assessment: This assessment involves reassessing the person's detailed history of transient loss of consciousness (TLoC), medical history, and any family history of cardiac disease or an inherited cardiac condition NICE CG109. A clinical examination, including a full cardiovascular examination and, if clinically appropriate, measurement of lying and standing blood pressure, should be conducted NICE CG109. A 12-lead ECG should be repeated, and any previous ECG recordings should be obtained and examined NICE CG109. Based on this assessment, the person is assigned to a suspected cause, such as suspected cardiac arrhythmic or suspected structural heart disease NICE CG109.
- Further Investigations for Suspected Cardiac Arrhythmic Cause:
- Ambulatory ECG: For people with a suspected cardiac arrhythmic cause of syncope, an ambulatory ECG should be offered NICE CG109. The type of ambulatory ECG (Holter monitoring, external event recorder, or implantable event recorder) is chosen based on the frequency of TLoC NICE CG109. An implantable loop recorder may be considered if there is an inheritable arrhythmia at low risk of sudden cardiac death NICE CKS.
- Exercise Testing: If the syncope occurred during exercise, urgent exercise testing should be offered, unless there is a possible contraindication NICE CG109. Syncope during exercise may also benefit from exercise testing NICE CKS.
- Echocardiogram: An echocardiogram is recommended if structural heart disease is suspected, or if syncope is suspected secondary to a cardiac cause NICE CKS,NICE CKS. This is also indicated if a murmur is found on examination, heart failure is suspected, or the ECG shows signs like left bundle branch block, left ventricular hypertrophy, or Q-waves NICE CKS.
- Electrophysiological Study: Further specialist investigations may include an electrophysiological study to assess suspected bradycardia or tachycardia NICE CKS.